4- Set up reflux system using a clean and dry condenser . 5- Place the flask on the hot plate and heat the reaction for 45 minutes - 1 hour . 6- When the reflux is over , remove magnetic stirrer and allow the reaction to cool to room temperature . 7- Add 20 ml of ice water to a separating funnel
We added sodium carbonate until the pH of the mixture was 8. After neutralize, we collected benzocaine by vacuum filtration. We used a Buchner funnel to collect benzocaine. We used three 10 ml of water to wash the product. After the product was dry, we weighed, calculate the percent yield and determined the melting point of the product.
Equation 1: Absolute Error = Experimental Value – Accepted Value Equation 2: Standard Deviation: Equation 3: Density (ρ) = Mass (m) / Volume (V) Equation 4: General Methods and Materials: In this experiment, the materials used were provided by California State University, Fresno chemistry stockroom. We used a lab coat and lab goggles. The materials used was a 10mL volumetric flask, and an electric balance. Procedure: In order to begin the experiment we need to understand our objectives. Know how to use an electronic balance, calibrate glassware, and know how to use a volumetric flask, calculate density and know how to calculate the percent error.
Use the wash bottle with deionised water to transfer all the oxalic acid crystals from the glass beaker to the funnel. 11. Rinse out all the oxalic acid crystals with the wash bottle from the funnel in the volumetric flask. 12. Add deionized water to the volumetric flask to the 250ml mark on the volumetric flask.
Dissolve the salt in 60 ml of tap water. Add 30 ml 6 M Hcl and stir the mixture with a glass rod. Add 12 g solid Nacl to the solution and stir the mixture for about 2 minutes. Support a 250 ml separatory funnel on a ring, making sure that the stopcock is closed and that a clean beaker is placed beneath the exit tube. Transfer the aqueous solution from the beaker to the separatory funnel.
In 10 g dried sediment sample added 7 ml 0.2 M NH4Cl solution. A mixture of 100 ml hexane: acetone (1:1) was used as a solvent to extract pesticides with overnight shaking for 12 h on reciprocal or wrist action shaker at 180 rpm. The extract was carefully decanted through activated florisil column (2-3 cm), giving twice wash with25 ml hexane: acetone (1:1) to the sediments. The elute was then washed with 200 ml water and then again aqueous layer was extracted with 50 ml hexane. Finally the hexane layer was washed with 100 ml water and then evaporated to dryness with a vacuum rotary evaporator.
Connect the spectrometer to Labquest and select a new file. Calibrate the spectrometer by placing the blank inside and allowing the lamp to warm up. The optimal wavelength for the standard curve and data collection can be started at this stage. Empty the blank and use the solution from test tube one to rinse the cuvette twice. Fill it ¾ with solution one, wipe the outside, and place it in the spectrometer.
Apparatus- Chromatography column: C18 (10 microns particle size), with Guard column Flow rate: 1.2ml/min Pressure: 30-40kgf Wavelength: 326nm Mobile phase: methanol : water (95:5 v/v) Internal standard: retinyl acetate Injection volume: 20µl Procedure for Retinol extraction from serum samples- 1) 100 µl of serum sample and 100 µl of Retinyl acetate were added into 12 X 100mm glass test tubes. Vortex-mixed for 30 seconds. Then, kept them at 4 C for 5 mins. 2) 1mL of hexane was added and vortex-mixed intermittently for 60 sec. 3) Centrifuged at 2500 rpm for 12 mins.
Then, the test media is then incubated at 37 ° C, for 18-24 hours. Rinsing reusable instruments The samples were rinsed with 40 ml of pyrogen-free water using a glass beaker that is free from pyrogens. Endotoxin testing using STV A total of 0,2mL from the water obtained from the rinsing was placed in the STV containing LAL reagent and was shaken for 20 to 30 seconds. Then STV was placed in an incubator at 37 ° C for 60 ± 2 minutes. STV was then observed by reversing the reaction tube in one smooth motion.
Making tea solution: Take around 3 gram of tea from tea bags and record the weight with an uncertainty of ± 0.001 using an high accuracy balance. Take 400 ml beaker add 200 ml of distilled water to it. Start heating it up with the bunsen burner until 150ml remain. (recommended ratio of 1 g of tea : 50ml of water) Measure the temperature of water and wait till it reach the expected value Add the tea leaf once the water is 150ml(some will evaporate during the heating) and keep the temperature at a constant degrees by using a water bath. Using a stopwatch to determine the amount of heating time.